-
Notifications
You must be signed in to change notification settings - Fork 0
/
trie.go
682 lines (628 loc) · 21.4 KB
/
trie.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
// (c) 2020-2021, Lux Partners Limited.
//
// This file is a derived work, based on the go-ethereum library whose original
// notices appear below.
//
// It is distributed under a license compatible with the licensing terms of the
// original code from which it is derived.
//
// Much love to the original authors for their work.
// **********
// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Package trie implements Merkle Patricia Tries.
package trie
import (
"bytes"
"errors"
"fmt"
"github.com/luxfi/coreth/core/types"
"github.com/luxfi/coreth/trie/trienode"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/log"
)
// Trie is a Merkle Patricia Trie. Use New to create a trie that sits on
// top of a database. Whenever trie performs a commit operation, the generated
// nodes will be gathered and returned in a set. Once the trie is committed,
// it's not usable anymore. Callers have to re-create the trie with new root
// based on the updated trie database.
//
// Trie is not safe for concurrent use.
type Trie struct {
root node
owner common.Hash
// Flag whether the commit operation is already performed. If so the
// trie is not usable(latest states is invisible).
committed bool
// Keep track of the number leaves which have been inserted since the last
// hashing operation. This number will not directly map to the number of
// actually unhashed nodes.
unhashed int
// reader is the handler trie can retrieve nodes from.
reader *trieReader
// tracer is the tool to track the trie changes.
// It will be reset after each commit operation.
tracer *tracer
}
// newFlag returns the cache flag value for a newly created node.
func (t *Trie) newFlag() nodeFlag {
return nodeFlag{dirty: true}
}
// Copy returns a copy of Trie.
func (t *Trie) Copy() *Trie {
return &Trie{
root: t.root,
owner: t.owner,
committed: t.committed,
unhashed: t.unhashed,
reader: t.reader,
tracer: t.tracer.copy(),
}
}
// New creates the trie instance with provided trie id and the read-only
// database. The state specified by trie id must be available, otherwise
// an error will be returned. The trie root specified by trie id can be
// zero hash or the sha3 hash of an empty string, then trie is initially
// empty, otherwise, the root node must be present in database or returns
// a MissingNodeError if not.
func New(id *ID, db *Database) (*Trie, error) {
reader, err := newTrieReader(id.StateRoot, id.Owner, db)
if err != nil {
return nil, err
}
trie := &Trie{
owner: id.Owner,
reader: reader,
tracer: newTracer(),
}
if id.Root != (common.Hash{}) && id.Root != types.EmptyRootHash {
rootnode, err := trie.resolveAndTrack(id.Root[:], nil)
if err != nil {
return nil, err
}
trie.root = rootnode
}
return trie, nil
}
// NewEmpty is a shortcut to create empty tree. It's mostly used in tests.
func NewEmpty(db *Database) *Trie {
tr, _ := New(TrieID(types.EmptyRootHash), db)
return tr
}
// MustNodeIterator is a wrapper of NodeIterator and will omit any encountered
// error but just print out an error message.
func (t *Trie) MustNodeIterator(start []byte) NodeIterator {
it, err := t.NodeIterator(start)
if err != nil {
log.Error("Unhandled trie error in Trie.NodeIterator", "err", err)
}
return it
}
// NodeIterator returns an iterator that returns nodes of the trie. Iteration starts at
// the key after the given start key.
func (t *Trie) NodeIterator(start []byte) (NodeIterator, error) {
// Short circuit if the trie is already committed and not usable.
if t.committed {
return nil, ErrCommitted
}
return newNodeIterator(t, start), nil
}
// MustGet is a wrapper of Get and will omit any encountered error but just
// print out an error message.
func (t *Trie) MustGet(key []byte) []byte {
res, err := t.Get(key)
if err != nil {
log.Error("Unhandled trie error in Trie.Get", "err", err)
}
return res
}
// Get returns the value for key stored in the trie.
// The value bytes must not be modified by the caller.
//
// If the requested node is not present in trie, no error will be returned.
// If the trie is corrupted, a MissingNodeError is returned.
func (t *Trie) Get(key []byte) ([]byte, error) {
// Short circuit if the trie is already committed and not usable.
if t.committed {
return nil, ErrCommitted
}
value, newroot, didResolve, err := t.get(t.root, keybytesToHex(key), 0)
if err == nil && didResolve {
t.root = newroot
}
return value, err
}
func (t *Trie) get(origNode node, key []byte, pos int) (value []byte, newnode node, didResolve bool, err error) {
switch n := (origNode).(type) {
case nil:
return nil, nil, false, nil
case valueNode:
return n, n, false, nil
case *shortNode:
if len(key)-pos < len(n.Key) || !bytes.Equal(n.Key, key[pos:pos+len(n.Key)]) {
// key not found in trie
return nil, n, false, nil
}
value, newnode, didResolve, err = t.get(n.Val, key, pos+len(n.Key))
if err == nil && didResolve {
n = n.copy()
n.Val = newnode
}
return value, n, didResolve, err
case *fullNode:
value, newnode, didResolve, err = t.get(n.Children[key[pos]], key, pos+1)
if err == nil && didResolve {
n = n.copy()
n.Children[key[pos]] = newnode
}
return value, n, didResolve, err
case hashNode:
child, err := t.resolveAndTrack(n, key[:pos])
if err != nil {
return nil, n, true, err
}
value, newnode, _, err := t.get(child, key, pos)
return value, newnode, true, err
default:
panic(fmt.Sprintf("%T: invalid node: %v", origNode, origNode))
}
}
// MustGetNode is a wrapper of GetNode and will omit any encountered error but
// just print out an error message.
func (t *Trie) MustGetNode(path []byte) ([]byte, int) {
item, resolved, err := t.GetNode(path)
if err != nil {
log.Error("Unhandled trie error in Trie.GetNode", "err", err)
}
return item, resolved
}
// GetNode retrieves a trie node by compact-encoded path. It is not possible
// to use keybyte-encoding as the path might contain odd nibbles.
//
// If the requested node is not present in trie, no error will be returned.
// If the trie is corrupted, a MissingNodeError is returned.
func (t *Trie) GetNode(path []byte) ([]byte, int, error) {
// Short circuit if the trie is already committed and not usable.
if t.committed {
return nil, 0, ErrCommitted
}
item, newroot, resolved, err := t.getNode(t.root, compactToHex(path), 0)
if err != nil {
return nil, resolved, err
}
if resolved > 0 {
t.root = newroot
}
if item == nil {
return nil, resolved, nil
}
return item, resolved, nil
}
func (t *Trie) getNode(origNode node, path []byte, pos int) (item []byte, newnode node, resolved int, err error) {
// If non-existent path requested, abort
if origNode == nil {
return nil, nil, 0, nil
}
// If we reached the requested path, return the current node
if pos >= len(path) {
// Although we most probably have the original node expanded, encoding
// that into consensus form can be nasty (needs to cascade down) and
// time consuming. Instead, just pull the hash up from disk directly.
var hash hashNode
if node, ok := origNode.(hashNode); ok {
hash = node
} else {
hash, _ = origNode.cache()
}
if hash == nil {
return nil, origNode, 0, errors.New("non-consensus node")
}
blob, err := t.reader.node(path, common.BytesToHash(hash))
return blob, origNode, 1, err
}
// Path still needs to be traversed, descend into children
switch n := (origNode).(type) {
case valueNode:
// Path prematurely ended, abort
return nil, nil, 0, nil
case *shortNode:
if len(path)-pos < len(n.Key) || !bytes.Equal(n.Key, path[pos:pos+len(n.Key)]) {
// Path branches off from short node
return nil, n, 0, nil
}
item, newnode, resolved, err = t.getNode(n.Val, path, pos+len(n.Key))
if err == nil && resolved > 0 {
n = n.copy()
n.Val = newnode
}
return item, n, resolved, err
case *fullNode:
item, newnode, resolved, err = t.getNode(n.Children[path[pos]], path, pos+1)
if err == nil && resolved > 0 {
n = n.copy()
n.Children[path[pos]] = newnode
}
return item, n, resolved, err
case hashNode:
child, err := t.resolveAndTrack(n, path[:pos])
if err != nil {
return nil, n, 1, err
}
item, newnode, resolved, err := t.getNode(child, path, pos)
return item, newnode, resolved + 1, err
default:
panic(fmt.Sprintf("%T: invalid node: %v", origNode, origNode))
}
}
// MustUpdate is a wrapper of Update and will omit any encountered error but
// just print out an error message.
func (t *Trie) MustUpdate(key, value []byte) {
if err := t.Update(key, value); err != nil {
log.Error("Unhandled trie error in Trie.Update", "err", err)
}
}
// Update associates key with value in the trie. Subsequent calls to
// Get will return value. If value has length zero, any existing value
// is deleted from the trie and calls to Get will return nil.
//
// The value bytes must not be modified by the caller while they are
// stored in the trie.
//
// If the requested node is not present in trie, no error will be returned.
// If the trie is corrupted, a MissingNodeError is returned.
func (t *Trie) Update(key, value []byte) error {
// Short circuit if the trie is already committed and not usable.
if t.committed {
return ErrCommitted
}
return t.update(key, value)
}
func (t *Trie) update(key, value []byte) error {
t.unhashed++
k := keybytesToHex(key)
if len(value) != 0 {
_, n, err := t.insert(t.root, nil, k, valueNode(value))
if err != nil {
return err
}
t.root = n
} else {
_, n, err := t.delete(t.root, nil, k)
if err != nil {
return err
}
t.root = n
}
return nil
}
func (t *Trie) insert(n node, prefix, key []byte, value node) (bool, node, error) {
if len(key) == 0 {
if v, ok := n.(valueNode); ok {
return !bytes.Equal(v, value.(valueNode)), value, nil
}
return true, value, nil
}
switch n := n.(type) {
case *shortNode:
matchlen := prefixLen(key, n.Key)
// If the whole key matches, keep this short node as is
// and only update the value.
if matchlen == len(n.Key) {
dirty, nn, err := t.insert(n.Val, append(prefix, key[:matchlen]...), key[matchlen:], value)
if !dirty || err != nil {
return false, n, err
}
return true, &shortNode{n.Key, nn, t.newFlag()}, nil
}
// Otherwise branch out at the index where they differ.
branch := &fullNode{flags: t.newFlag()}
var err error
_, branch.Children[n.Key[matchlen]], err = t.insert(nil, append(prefix, n.Key[:matchlen+1]...), n.Key[matchlen+1:], n.Val)
if err != nil {
return false, nil, err
}
_, branch.Children[key[matchlen]], err = t.insert(nil, append(prefix, key[:matchlen+1]...), key[matchlen+1:], value)
if err != nil {
return false, nil, err
}
// Replace this shortNode with the branch if it occurs at index 0.
if matchlen == 0 {
return true, branch, nil
}
// New branch node is created as a child of the original short node.
// Track the newly inserted node in the tracer. The node identifier
// passed is the path from the root node.
t.tracer.onInsert(append(prefix, key[:matchlen]...))
// Replace it with a short node leading up to the branch.
return true, &shortNode{key[:matchlen], branch, t.newFlag()}, nil
case *fullNode:
dirty, nn, err := t.insert(n.Children[key[0]], append(prefix, key[0]), key[1:], value)
if !dirty || err != nil {
return false, n, err
}
n = n.copy()
n.flags = t.newFlag()
n.Children[key[0]] = nn
return true, n, nil
case nil:
// New short node is created and track it in the tracer. The node identifier
// passed is the path from the root node. Note the valueNode won't be tracked
// since it's always embedded in its parent.
t.tracer.onInsert(prefix)
return true, &shortNode{key, value, t.newFlag()}, nil
case hashNode:
// We've hit a part of the trie that isn't loaded yet. Load
// the node and insert into it. This leaves all child nodes on
// the path to the value in the trie.
rn, err := t.resolveAndTrack(n, prefix)
if err != nil {
return false, nil, err
}
dirty, nn, err := t.insert(rn, prefix, key, value)
if !dirty || err != nil {
return false, rn, err
}
return true, nn, nil
default:
panic(fmt.Sprintf("%T: invalid node: %v", n, n))
}
}
// MustDelete is a wrapper of Delete and will omit any encountered error but
// just print out an error message.
func (t *Trie) MustDelete(key []byte) {
if err := t.Delete(key); err != nil {
log.Error("Unhandled trie error in Trie.Delete", "err", err)
}
}
// Delete removes any existing value for key from the trie.
//
// If the requested node is not present in trie, no error will be returned.
// If the trie is corrupted, a MissingNodeError is returned.
func (t *Trie) Delete(key []byte) error {
// Short circuit if the trie is already committed and not usable.
if t.committed {
return ErrCommitted
}
t.unhashed++
k := keybytesToHex(key)
_, n, err := t.delete(t.root, nil, k)
if err != nil {
return err
}
t.root = n
return nil
}
// delete returns the new root of the trie with key deleted.
// It reduces the trie to minimal form by simplifying
// nodes on the way up after deleting recursively.
func (t *Trie) delete(n node, prefix, key []byte) (bool, node, error) {
switch n := n.(type) {
case *shortNode:
matchlen := prefixLen(key, n.Key)
if matchlen < len(n.Key) {
return false, n, nil // don't replace n on mismatch
}
if matchlen == len(key) {
// The matched short node is deleted entirely and track
// it in the deletion set. The same the valueNode doesn't
// need to be tracked at all since it's always embedded.
t.tracer.onDelete(prefix)
return true, nil, nil // remove n entirely for whole matches
}
// The key is longer than n.Key. Remove the remaining suffix
// from the subtrie. Child can never be nil here since the
// subtrie must contain at least two other values with keys
// longer than n.Key.
dirty, child, err := t.delete(n.Val, append(prefix, key[:len(n.Key)]...), key[len(n.Key):])
if !dirty || err != nil {
return false, n, err
}
switch child := child.(type) {
case *shortNode:
// The child shortNode is merged into its parent, track
// is deleted as well.
t.tracer.onDelete(append(prefix, n.Key...))
// Deleting from the subtrie reduced it to another
// short node. Merge the nodes to avoid creating a
// shortNode{..., shortNode{...}}. Use concat (which
// always creates a new slice) instead of append to
// avoid modifying n.Key since it might be shared with
// other nodes.
return true, &shortNode{concat(n.Key, child.Key...), child.Val, t.newFlag()}, nil
default:
return true, &shortNode{n.Key, child, t.newFlag()}, nil
}
case *fullNode:
dirty, nn, err := t.delete(n.Children[key[0]], append(prefix, key[0]), key[1:])
if !dirty || err != nil {
return false, n, err
}
n = n.copy()
n.flags = t.newFlag()
n.Children[key[0]] = nn
// Because n is a full node, it must've contained at least two children
// before the delete operation. If the new child value is non-nil, n still
// has at least two children after the deletion, and cannot be reduced to
// a short node.
if nn != nil {
return true, n, nil
}
// Reduction:
// Check how many non-nil entries are left after deleting and
// reduce the full node to a short node if only one entry is
// left. Since n must've contained at least two children
// before deletion (otherwise it would not be a full node) n
// can never be reduced to nil.
//
// When the loop is done, pos contains the index of the single
// value that is left in n or -2 if n contains at least two
// values.
pos := -1
for i, cld := range &n.Children {
if cld != nil {
if pos == -1 {
pos = i
} else {
pos = -2
break
}
}
}
if pos >= 0 {
if pos != 16 {
// If the remaining entry is a short node, it replaces
// n and its key gets the missing nibble tacked to the
// front. This avoids creating an invalid
// shortNode{..., shortNode{...}}. Since the entry
// might not be loaded yet, resolve it just for this
// check.
cnode, err := t.resolve(n.Children[pos], append(prefix, byte(pos)))
if err != nil {
return false, nil, err
}
if cnode, ok := cnode.(*shortNode); ok {
// Replace the entire full node with the short node.
// Mark the original short node as deleted since the
// value is embedded into the parent now.
t.tracer.onDelete(append(prefix, byte(pos)))
k := append([]byte{byte(pos)}, cnode.Key...)
return true, &shortNode{k, cnode.Val, t.newFlag()}, nil
}
}
// Otherwise, n is replaced by a one-nibble short node
// containing the child.
return true, &shortNode{[]byte{byte(pos)}, n.Children[pos], t.newFlag()}, nil
}
// n still contains at least two values and cannot be reduced.
return true, n, nil
case valueNode:
return true, nil, nil
case nil:
return false, nil, nil
case hashNode:
// We've hit a part of the trie that isn't loaded yet. Load
// the node and delete from it. This leaves all child nodes on
// the path to the value in the trie.
rn, err := t.resolveAndTrack(n, prefix)
if err != nil {
return false, nil, err
}
dirty, nn, err := t.delete(rn, prefix, key)
if !dirty || err != nil {
return false, rn, err
}
return true, nn, nil
default:
panic(fmt.Sprintf("%T: invalid node: %v (%v)", n, n, key))
}
}
func concat(s1 []byte, s2 ...byte) []byte {
r := make([]byte, len(s1)+len(s2))
copy(r, s1)
copy(r[len(s1):], s2)
return r
}
func (t *Trie) resolve(n node, prefix []byte) (node, error) {
if n, ok := n.(hashNode); ok {
return t.resolveAndTrack(n, prefix)
}
return n, nil
}
// resolveAndTrack loads node from the underlying store with the given node hash
// and path prefix and also tracks the loaded node blob in tracer treated as the
// node's original value. The rlp-encoded blob is preferred to be loaded from
// database because it's easy to decode node while complex to encode node to blob.
func (t *Trie) resolveAndTrack(n hashNode, prefix []byte) (node, error) {
blob, err := t.reader.node(prefix, common.BytesToHash(n))
if err != nil {
return nil, err
}
t.tracer.onRead(prefix, blob)
return mustDecodeNode(n, blob), nil
}
// Hash returns the root hash of the trie. It does not write to the
// database and can be used even if the trie doesn't have one.
func (t *Trie) Hash() common.Hash {
hash, cached := t.hashRoot()
t.root = cached
return common.BytesToHash(hash.(hashNode))
}
// Commit collects all dirty nodes in the trie and replaces them with the
// corresponding node hash. All collected nodes (including dirty leaves if
// collectLeaf is true) will be encapsulated into a nodeset for return.
// The returned nodeset can be nil if the trie is clean (nothing to commit).
// Once the trie is committed, it's not usable anymore. A new trie must
// be created with new root and updated trie database for following usage
func (t *Trie) Commit(collectLeaf bool) (common.Hash, *trienode.NodeSet, error) {
defer t.tracer.reset()
defer func() {
t.committed = true
}()
// Trie is empty and can be classified into two types of situations:
// (a) The trie was empty and no update happens => return nil
// (b) The trie was non-empty and all nodes are dropped => return
// the node set includes all deleted nodes
if t.root == nil {
paths := t.tracer.deletedNodes()
if len(paths) == 0 {
return types.EmptyRootHash, nil, nil // case (a)
}
nodes := trienode.NewNodeSet(t.owner)
for _, path := range paths {
nodes.AddNode([]byte(path), trienode.NewDeleted())
}
return types.EmptyRootHash, nodes, nil // case (b)
}
// Derive the hash for all dirty nodes first. We hold the assumption
// in the following procedure that all nodes are hashed.
rootHash := t.Hash()
// Do a quick check if we really need to commit. This can happen e.g.
// if we load a trie for reading storage values, but don't write to it.
if hashedNode, dirty := t.root.cache(); !dirty {
// Replace the root node with the origin hash in order to
// ensure all resolved nodes are dropped after the commit.
t.root = hashedNode
return rootHash, nil, nil
}
nodes := trienode.NewNodeSet(t.owner)
for _, path := range t.tracer.deletedNodes() {
nodes.AddNode([]byte(path), trienode.NewDeleted())
}
t.root = newCommitter(nodes, t.tracer, collectLeaf).Commit(t.root)
return rootHash, nodes, nil
}
// hashRoot calculates the root hash of the given trie
func (t *Trie) hashRoot() (node, node) {
if t.root == nil {
return hashNode(types.EmptyRootHash.Bytes()), nil
}
// If the number of changes is below 100, we let one thread handle it
h := newHasher(t.unhashed >= 100)
defer func() {
returnHasherToPool(h)
t.unhashed = 0
}()
hashed, cached := h.hash(t.root, true)
return hashed, cached
}
// Reset drops the referenced root node and cleans all internal state.
func (t *Trie) Reset() {
t.root = nil
t.owner = common.Hash{}
t.unhashed = 0
t.tracer.reset()
t.committed = false
}